Conversion of high boiling hydrocarbon oil



Nov. 10, 1931. I ,w. E. WARWICK 1,830,972

CONVERSION OF HIGH BOILING HYDROGARBON OIL Filed Nov. 9, 1925 g I 7 g Patented Nov. 10, 1931 UNITED STATES PATENT OFFICE WILLIAM E. WARWICK, OF CHICAGO, ILLINOIS, ASSIGNOR TO STANDARD OIL COMPANY, OF WRITING, INDIANA, A CORPORATION OF INDIANA.

CONVERSION OF HIGH BOILING HYDROOARBON OIL Application filed November The present invention relates to improve 'ments in the conversion of hi h boilinghydrocarbon oils into lower boiling hydrocarbon oils, and will be fully understood from the following description illustrated by the accompanying drawing, in which apparatus suitable for carrying the invention into effeet is diagrammaticallyillustrated.

Referring more particularly to the drawing, the numeral 5 indicates a furnace setting in which is mounted a coil 6, to which the oil to be subjectedto the conversion proc-' ess is supplied through the line 7 From the coil 6,. the oil heated therein passes out 1 through the line 8 and is discharged through lines 9 and 10, independently controlled by valves 11 and 12 respectively, into the enlarged chambers 13 and 14. Residualproducts may be withdrawn from the enlarged 2o chambers 13 and 14 through the valved lines 15 and 16 respectively.

From the enlarged chamber 13 vapors pass through a conduit 17 into the lower portion of the dephlegmator 18. From the upper 25 portion of the chamber 14, a similar vapor line 19 conducts the vapors discharged into the lower portion of a dephlegmator 20..

Vapors uncondensed in dephlegmator 18 pass off through vapor line 21 to suitable condensao ing, collecting and pressure maintaining devices (not shown). Similarly, vapors uncondensed in the dephlegmating tower pass out through the vapor line 22 to suitable condensing, collecting and pressure maintaining devices.

Condensate formed in the dephlegmating tower 18 may be withdrawn through the line 23 and forced by suitable means, for example,

surge pump 24, through valve controlled line 40 25 into the inlet line 7 leading into the coil 6. Condensate formed in the dephlegmator 20 is similarly Withdrawn through line 26 by surge pump 27 or other suitable means, and forced through the valve controlled line 28 into the inlet 7 of the coil 6.

In order to provide a desired controllable reflux in the dephlegmating towers 18 and 20, the cooling coils 29 and 30 are provided in the upper portions of said towers respec- 60 tively. A suitable cooling medium, prefer- 9, 1925. Serial No. 67,825.

ably the stock to be charged into the system, 1s supplied to the coils 29 and 30 from the manifold 31 through the valve controlled lines 32 and 33 respectively. The supply of cooling medium to the coils of the dephlegmating towers is therefore independently controllable. From the coils 29 and30 the oil, preheated in the dephlegmators, passes through the valve controlled lines 34 and 35 respectively to the inlet 7 of the coil 6. Such oil may likewise be supplied to the inlet 7 through the valve controlled supply line 36, if desired or if found necessary. In operation for the production of low boil mg hydrocarbon oils, for example, of the type of gasoline, the higher boiling oil to be subjected to conversion is fed through the supply ,hne 7 into and through the coil 6, in which it is heated to conversion temperatures above 700 F. From the coil 6 the heated oil passes through the line 8 and through the independently controllable lines 9 and 10 into the enlarged chambers 13 and 14: respectively. As pointed out hereinafter, conditions of operation in each of these enlarged chambers is independently controllable in all respects.

Referring more particularly to the chamber 13, the feed of oil'thereto is independently controlled by means of the valve 11 in the line 9, and the withdrawal of oil therefrom is controlled by the valve in line 15. It is thus apparent that the rate of flow of oil through the chamber 13 and the duration of its retention therein are completely controllable. The chamber 13 is mildly heated or otherwise prevented from, falling .below conversion temperature, so that a substantial conversion of the oil takes place therein. Thus, oil may be heated in the coil 6 to -7 75 to 825 F., and may be retained at temperatures of from 750 to 825 F. in the chamber 13.

Va ors separated from the oil body in the chem er 13 pass out through the line 17 into the dephlegmator 18, in the upper portion of which is provided reflux cooling coil 29. Reflux condensate collected in the base of the tower passes out through the line 23 and is forced b pump 24 into the inlet 7 of the coil 6. X cooling medium, preferably oil of the nature of the stock charged into the sysa vtem for conversion, is supplied to the coil 18 and the enlarged chamber 13, in which vaporization takes place, may be controlled by any suitable means.

In a similar manner, the operation of conversion in the chamber 14 may be separately and independently controlled. The oil preheated to. conversion temperatures of above 700 F. (say 775 to 825 F.) in the coil 6 flows into the chamber 14 through the line 10 controlled by valve 12. Unvaporized residue is discharged through the independently controllable line 16. Vapors pass ofl through the vapor line 19 into an independently controllable dephlegmating tower 20, the reflux cooling action of which is controlled by the supply of oil through the'valve line 33 to the cooler 30, the oil thus used being subsequently passed through the line 35 into the supply line 7 of the coil 6. Independent pressure control may be maintained upon the dephlegmator 20 and the enlarged chamber 14.

In the operation of the device, for example, the flow of oil through the coil 6 may be so controlled that a temperature of approximately 800- F. is reached by the oil at the outlet thereof, the conversion taking place in the coil not exceeding 10%. The pressure maintained upon the coil may be, for example, 400 to 450 pounds. From 30 to 40% of the 011 discharged from the coil 6 may be fed into the enlarged chamber 13, in which it is maintained at a conversion temperature of 750 to 775 F. This chamber may be maintained at a pressure of 350 to 375 pounds, this pressure extending through the dephlegmating system and condenser (not shown), if desired. The remainder of the oil is supplied to the enlarged chamber 14, in which'a pres-- sure of approximately 250 pounds may be maintained. A more extenslve vaporization takes place in the enlarged chamber 14, and the oil, under these circumstances, is preferably maintained in the chamber for a somewhat shorter period of time than in the case of chamber 13. Thus, a conversion amounting to 20 to 30% may take place in the chamber 13, whereas that taking place in the chamber 14 may amount to only 15 to 20%. By reason of the more extensive vaporization taking place in the chamber 14, a somewhat lower temperature will be maintained therein than in the chamber 13.

It is thus apparent that, in accordance with the present invention, varying conditions of operation may be employed in efiecting the conversion of the oil passing through the coil 6. It is, of course, apparent that'identical conditions of operation may be maintained in the chambers 13 and 14 if desired. The apparatus and process of this maintained, in

invention are particularly adapted for experimental work in determining the roper conditions for operating upon oils 0 var ing characteristics. It is likewise y adapted for commercial operations where extreme flexibility of control of conditions is desired.

I claim:

1. The method of converting high-boiling hydrocarbon oils into lower boiling oils such as gasoline which comprises passing such oils in a continuously flowing stream through a heated zone in which they are heated to conversion temperature, subsequently assing the oil in divided streams into a urality of enlarged chambers in which di erential conversion .tem eratures and pressures are ependently controlling the supply of said heated oil delivered into each of said chambers, independently withdrawing oil from each of said chambers, inde pendently controlling the pressure in each of said chambers, said pressure conditions within the said chambers and said supply of oil to said chambers bein controlled to effect substantially difl'erentia conversion of the oil therein, separately withdrawin and cooling vapors from each of said e arged chambers to condense therefrom portions heavier than the desired distillate product, and returnin such condensates to the stream in the heated zone.

2. The method of converting high-boiling ch they are heated to Y are maintained, in ependentlg controlling elivered into the supply of said heated oil each of said chambers,independently withdrawingoil from each of said chambers, independently controlling the pressure in each of said chambers to efiect a substantially greater conversion of the oil in one than in the other of said chambers, separately withdrawing and cooling vapors from each of said chambers to condense therefrom ortions heavier than the desired disti ate product, and returning such condensates to the stream of oil in the heated zone.

3. The method of converting high-boilin hydrocarbon oils into lower boiling oils such as gasoline which comprises passing such oils in a continuously flowing stream through a heated zone in which they are heated to conversion temperature, subsequenty passing the oil in divided streams into a plurality of enlarged chambers in which differential conversion conditions are maintained, independentl controlling the of said chambers, the supply of oil to said chambers being controlled to cause the oil in one of said chambers to remain therein at conversion temperature for a substantially lon er period of time than in the other of said chambers, separately withdrawing and cooling vapors from each of said enlarged chambers to condense therefrom portions heavier than the desired distillate product, and returning such condensates to the stream of oil in the heated zone.

WILLIAM E. WARWICK." 

